1. Field of the Invention
The present invention relates to a Battery Management System (BMS). More particularly, the present invention relates to a BMS used in a vehicle using electrical energy.
2. Description of the Related Art
Vehicles with an internal combustion engine using gasoline or diesel fuel have caused serious air pollution. Accordingly, efforts have recently been made for developing electric or hybrid vehicles to reduce air pollution.
An electric vehicle uses a battery motor operating by electrical energy output by a battery. Since the electric vehicle mainly uses a battery formed by one battery pack including a plurality of rechargeable/dischargeable secondary cells, there is merit in that it produces no emission gases and less noise.
A hybrid vehicle commonly refers to a gasoline-electric hybrid vehicle that uses gasoline to power an internal-combustion engine and a battery to power an electric motor. Recently, hybrid vehicles using an internal-combustion engine and fuel cells and hybrid vehicles using a battery and fuel cells have been developed. The fuel cells directly obtain electrical energy by generating a chemical reaction while hydrogen and oxygen are continuously provided.
Since battery performance directly affects a vehicle using electrical energy, it is necessary for each battery cell to have exceptional performance. Also, it is necessary to provide a Battery Management System (BMS) to measure a voltage and a current of the battery pack to efficiently manage charging and discharging operations of each battery cell.
However, since a battery voltage and a threshold voltage range are compared to determine a battery overcharge, a battery may be continuously overcharged when a battery voltage detecting circuit has an error.